Age | Commit message (Collapse) | Author | |
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2009-02-14 | powerpc/44x: Support for 256KB PAGE_SIZE | Yuri Tikhonov | |
This patch adds support for 256KB pages on ppc44x-based boards. For simplification of implementation with 256KB pages we still assume 2-level paging. As a side effect this leads to wasting extra memory space reserved for PTE tables: only 1/4 of pages allocated for PTEs are actually used. But this may be an acceptable trade-off to achieve the high performance we have with big PAGE_SIZEs in some applications (e.g. RAID). Also with 256KB PAGE_SIZE we increase THREAD_SIZE up to 32KB to minimize the risk of stack overflows in the cases of on-stack arrays, which size depends on the page size (e.g. multipage BIOs, NTFS, etc.). With 256KB PAGE_SIZE we need to decrease the PKMAP_ORDER at least down to 9, otherwise all high memory (2 ^ 10 * PAGE_SIZE == 256MB) we'll be occupied by PKMAP addresses leaving no place for vmalloc. We do not separate PKMAP_ORDER for 256K from 16K/64K PAGE_SIZE here; actually that value of 10 in support for 16K/64K had been selected rather intuitively. Thus now for all cases of PAGE_SIZE on ppc44x (including the default, 4KB, one) we have 512 pages for PKMAP. Because ELF standard supports only page sizes up to 64K, then you should use binutils later than 2.17.50.0.3 with '-zmax-page-size' set to 256K for building applications, which are to be run with the 256KB-page sized kernel. If using the older binutils, then you should patch them like follows: --- binutils/bfd/elf32-ppc.c.orig +++ binutils/bfd/elf32-ppc.c -#define ELF_MAXPAGESIZE 0x10000 +#define ELF_MAXPAGESIZE 0x40000 One more restriction we currently have with 256KB page sizes is inability to use shmem safely, so, for now, the 256KB is available only if you turn the CONFIG_SHMEM option off (another variant is to use BROKEN). Though, if you need shmem with 256KB pages, you can always remove the !SHMEM dependency in 'config PPC_256K_PAGES', and use the workaround available here: http://lkml.org/lkml/2008/12/19/20 Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com> | |||
2008-12-29 | powerpc/44x: Support 16K/64K base page sizes on 44x | Ilya Yanok | |
This adds support for 16k and 64k page sizes on PowerPC 44x processors. The PGDIR table is much smaller than a page when using 16k or 64k pages (512 and 32 bytes respectively) so we allocate the PGDIR with kzalloc() instead of __get_free_pages(). One PTE table covers rather a large memory area when using 16k or 64k pages (32MB or 512MB respectively), so we can easily put FIXMAP and PKMAP in the area covered by one PTE table. Signed-off-by: Yuri Tikhonov <yur@emcraft.com> Signed-off-by: Vladimir Panfilov <pvr@emcraft.com> Signed-off-by: Ilya Yanok <yanok@emcraft.com> Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> | |||
2008-09-24 | POWERPC: Allow 32-bit hashed pgtable code to support 36-bit physical | Becky Bruce | |
This rearranges a bit of code, and adds support for 36-bit physical addressing for configs that use a hashed page table. The 36b physical support is not enabled by default on any config - it must be explicitly enabled via the config system. This patch *only* expands the page table code to accomodate large physical addresses on 32-bit systems and enables the PHYS_64BIT config option for 86xx. It does *not* allow you to boot a board with more than about 3.5GB of RAM - for that, SWIOTLB support is also required (and coming soon). Signed-off-by: Becky Bruce <becky.bruce@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> | |||
2008-08-04 | powerpc: Move include files to arch/powerpc/include/asm | Stephen Rothwell | |
from include/asm-powerpc. This is the result of a mkdir arch/powerpc/include/asm git mv include/asm-powerpc/* arch/powerpc/include/asm Followed by a few documentation/comment fixups and a couple of places where <asm-powepc/...> was being used explicitly. Of the latter only one was outside the arch code and it is a driver only built for powerpc. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org> |